"This is a new effort which is being asked of you. The army has been requested to help" combat the virus, Lieutenant-Colonel Raul Barca told about 100 freshly-mobilised reservists, all wearing facemasks.

Small groups of men and women from the "Hospital 2 Battalion", some carrying rifles on their shoulders, arrived in military trucks on Sunday at the Moudon military base in the Vaud region of western Switzerland.

All of them had received a call or text message from the army on Friday giving them 48 hours' notice to report for a deployment that could last until the end of March.

Their work on the Covid front line is set to start on Tuesday.

During the first wave of the pandemic, which hit Europe in the spring, the Swiss army was called in to help out the country's 26 regional cantons.

However, this time, "the situation is different... the hospital staff are more affected, tired", Barca told the troops on the parade ground.

In total, more than 200 reservists -- who underwent four months of health training -- reported for duty on Sunday to support Swiss hospitals which are saturated with the arrival of new Covid-19 patients.

David Moreira, 21, a security guard in Geneva who completed his military service earlier this year, was preparing to tackle his first engagement in the field.

"I received the mobilisation order when I came back from work," he said, adding that he was enthusiastic about the "idea of helping" the public.

- Deaths doubling -

Florine Orth, 25, who works in the watchmaking sector in Biel, northwestern Switzerland, was calm about her first call-up.

Her only concern was that "we don't know what state the patients will be in," she told AFP, nonetheless feeling "great pride" in taking part in the fight against the pandemic.

Since the start of October, Covid-19 hospitalisations, intensive care admissions and deaths have been roughly doubling in Switzerland every week.

And the number of positive tests is exploding.

This weekend, Geneva was the worst-affected region in Europe in terms of the incidence of confirmed new cases over the past 14 days, according to statistics compiled by Swiss public television.

The rate on Monday stood at 2,724 positive tests per 100,000 people over the previous fortnight in Geneva.

Overwhelmed by the virus, Geneva and the nearby western cantons of Wallis, Bern, Vaud and Fribourg sought out the support of the military, whose members will help relieve the burden of ambulance workers and provide basic care to coronavirus patients.

Around 170 volunteer soldiers are already at work in Fribourg.

To cope with the influx of coronavirus patients, some of those in intensive care are being transferred to less-crowded hospitals in the east.

- Time for action -

Considered one of the founding pillars of the famously-neutral country, the Swiss army is organised like a militia.

Overseen by a few thousand professionals, conscripts do at least four months' military service before being called up every year for three-week training sessions.

During the first wave of the pandemic, the army said it could mobilise up to 8,000 soldiers to help relieve the pressure on hospitals in the country of 8.5 million people.

Following criticisms of the way that deployment was handled -- some soldiers complained of not having been given enough to do -- the procedure for calling in the army has been revised.

This time, the government decided to mobilise only up to 2,500 soldiers, and on condition that cantons make the request and can show that "civilian resources have been exhausted".

However, this time there is no question of the soldiers being under-employed.

"They need work and they need action that will be useful both for the hospitals and for themselves," said Yvon Langel, the commander of 1 Territorial Division.

Nearby, the called-up reservists fill out a health questionnaire. They then head to the army pharmacy for a temperature check, flu jab and a Covid-19 test.

All being well, they will be serving in Switzerland's hospitals on Tuesday.